Tryptanthrin is an indole quinazoline that could be an alkaloid from indigo-bearing plants. Tryptanthrin is a potent and orally active cellular Leukotriene (LT) biosynthesis inhibitor. Tryptanthrin has anticancer activity. Tryptanthrin suppresses the expression levels of NOS1, COX-2, and NF-kappaB and regulates the expression levels of IL-2, IL-10, and TNF-alpha[1][2].